Pedal travel simulators in power-assisted hydraulic vehicle braking systems allow a pedal travel (for a parking brake, a lever travel) when a master brake cylinder is actuated. During a power-assisted actuation, the master brake cylinder is used as a setpoint generator for a hydraulic brake pressure that is generated not with the master brake cylinder, but, rather, with external energy using a hydropump, for example. During power braking, the master brake cylinder is hydraulically disconnected from the vehicle braking system, for example by closing a valve, and, when actuated, displaces brake fluid into the pedal travel simulator.
A pedal travel simulator generally has a cylinder and a piston that is displaceable in the cylinder, as well as a piston spring that acts on the piston against a displacement direction. During a power-assisted actuation of a vehicle braking system, the pedal travel simulator is hydraulically connected to a master brake cylinder, which, when actuated, displaces brake fluid into the cylinder of the pedal travel simulator, as the result of which the piston is displaced in the cylinder, against an elastic force of the piston spring.